If both my DSL and PSP were not hacked....I'd go for the PSP hands down (video, music, internet, photos as well as games).

Having both of them hacked, I prefer the DSL (makes a better music player with a flashcart, has 'more' and smaller games and better homebrew, excluding emulators, but DSx86 makes a world of difference for me as compared to the PSP DOSBox which sux).

My only problems with the DSL sans the flashcart is that it's strictly (well mostly) a gaming console. And for those games that appear on both consoles, without fail, I prefer the PSP versions (FIFA 2010, Ironman, some of the FF series, etc...).